This invention relates generally to apparatus for collating different documents into a plurality of stacks and for advancing the collated stacks along a predetermined path toward a using station.
By way of example, the documents which are collated by the apparatus of the invention may be advertisements which are printed separately from a newspaper and which subsequently are inserted into or grouped with the newspaper for delivery to the consumer. Such advertisements conventionally are called "inserts" while the main body of the newspaper conventionally is called a "jacket".
Typically, various advertising inserts are printed at various locations and are collected at the newspaper publisher's plant for collating and for grouping with the jackets printed by the publisher. The jackets are usually carried in spaced pockets of a continuously moving conveyor which advances successive pockets at high speeds through a receiving station where inserts are added to each jacket. The conveyor serves as the so-called host machine for the collating apparatus.
Advertising inserts typically are made of thin, lightweight and relatively porous paper which is difficult to handle and feed. Because of the porosity of the paper, the use of conventional vacuum cups for picking up and transferring inserts in the collating operation is disadvantageous. The vacuum produced by such cups acts through the porous paper and tends to cause multiple inserts to stick together thereby making it difficult for the cups to pick up and transfer one insert at a time.